The present invention relates to a method for detecting fire, in particular to detect fire with light section image to sense smoke.
In most cases, the presence of smoke in fire is earlier than that of open fire, so a smoke-sensing fire detector has been applied widely. At present, the smoke-sensing fire detectors used in various places include ionic smoke-sensing fire detectors, photoelectric smoke-sensing fire detectors, as well as the analog alarm type fire detectors and automatic floating type fire detectors responding to a threshold, which have the primary intelligence. The existing fire detectors may alarm in error or late due to the color of the smoke, the size of the particles, the height of the space, airflow, and shake, etc., and alarm in error or miss the alarm due to the dust accumulation and the environmental variation.
Accordingly, it is an object of the present invention to provide a method for detecting fire with a smoke-sensing light section image to achieve a high sensitivity to flaming fire and non-flaming fire, high anti-interference ability, low error alarm ratio, and adaptation to the large space.
The method of the present invention is implemented as follows.
According to one aspect of the present invention, there is provided a method for detecting fire with a smoke-sensing light section image, characterized in that infrared radiation arrays and infrared cameras are provided in a monitored area, the infrared light beams emitted by the infrared radiation array pass through the monitored area, and the infrared light spots are imaged on the light target arrays of the infrared cameras, the images of the infrared light spots are converted into video signals by the infrared cameras, and then transferred to a video switcher, the video switcher sends the video signals received from the infrared cameras to a computer one by one in polling manner, and wherein after the video signals are input to a computer, the computer analyzes and processes the variation of the video signals in the manner of template matching, tendency analysis and correlation analysis, the computer controls an alarm unit to alarm by a linkage if fire is sensed.
The advantages of the present invention are in that:
(1) The light section formed by multi-beam light can cover the protected space in arbitrary curved surface, so that the area of the fast response region is greatly increased, and then it is possible to alarm in a large space early.
(2) Correlation analysis for adjacent beams in the light section can eliminate the error alarm caused by accidental factors in a single-beam of light fire alarm unit.
(3) The shift of operating conditions caused by dust accumulation is detected and traced automatically. When the shift exceeds a given range, a faulty signal is produced automatically. Meanwhile, such a fire detector can automatically modify the operating parameters thereof in accordance with the variation of the environment, so that the error and missed alarm caused by the dust accumulation and the environmental variation are reduced significantly.
(4) Surface imaging auto-tracing fixed-point detection may completely solve the problems of the error alarm caused by installing and moving the conventional linear smoke-sensing unit.
(5) By using the technique of surface imaging, the method for sensing smoke with light section image is capable of distinguishing an emitting light source from an interference light source. Therefore, the anti-interference performance of the system is enhanced, and then the application fields are enlarged widely.
The method of the present invention may be applied to the fire detection in a large and long space. It can achieve the abilities to adapt various environments, to acquire information with low cost, to install facilely, and to install in multi-layers.